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981.
Silvia Ribeiro de Souza e Silva Luiz Claúdio de Almeida Barbosa Beatriz King-Diaz Blas Lotina-Hennsen 《Pesticide biochemistry and physiology》2007,87(2):109-114
3,4-Seco-friedelan-3-oic acid was isolated from Maytenus imbricata (Celastraceae). At low concentrations it inhibited non-cyclic electron transport and ATP synthesis in spinach chloroplasts, i.e., it behaved as a Hill reaction inhibitor, and at high concentrations it acts as an uncoupler by enhancing uncoupled electron transport and Mg2+-ATPase activity. 3,4-Seco-friedelan-3-oic acid did not inhibit PSII electron transport from DPC to DCPIPox and photosystem I activity, but it enhanced from TMQH2 to MV, corroborating its action as uncoupler. It inhibits electron flow through PSII from water to sodium silicomolybdate. The whole results indicate that the 3,4-seco-friedelan-3-oic acid target is at the OEC complex enzyme, the donor side of PSII. The fluorescence decay data shows the formation of the K-band, which match this result, acting as inhibitor at the donor side of PSII and it as an uncoupler. 相似文献
982.
983.
鹅黑素皮质素受体-4基因的克隆与序列分析 总被引:6,自引:1,他引:6
黑素皮质素受体-4(Melanocortin receptor-4,MC4R)是其黑素皮质素受体MCR(MC1-5R)家族成员之一,属G蛋白偶联受体。它可与瘦蛋白、神经肽、α-黑素细胞刺激素等一起调节动物体重和采食量。参考鸡MC4R基因序列设计引物,克隆并测序了鹅MC4R基因。结果表明,鹅MC4R基因编码区全长996 bp,其核苷酸序列与鸡的同源性为95.3%,与人、牛、猪等哺乳动物同源性在75%-79%;其氨基酸序列与鸡的同源性达到98.5%。构建哺乳类、鸟类和鱼类MC4R基因核苷酸进化树显示,鹅较早地与哺乳类动物分化开来。分析MC4R蛋白的氨基酸残基特性参数表明,MC4R的7次跨膜结构与MC4R的亲水性区域、电荷密度以及氨基酸残基位于表面概率的变化规律相一致。 相似文献
984.
985.
Pogonatherum paniceum (Lam.) Hack. is a rock plant with good potential for vegetative recovery on naked lands. A high frequency in vitro regeneration system was developed for P. paniceum. Calli were induced from explants of mature seeds, seedlings, young leaves, and stem segments on Murashige and Skoog (MS) medium supplemented with 1.0 mg L−1 2,4-dichlorophenoxyacetic acid (2,4-D), 2.0 mg L−1 α-naphthalene acetic acid (NAA) and 0.2 mg L−1 6-benzylaminopurine (BAP). High induction rates (59.57%) and regeneration rates (100%) were obtained from mature seed explants; calli were sub-cultured for over 2 years and still retained a high regenerative capacity. One seed explant resulted in 69,997 plants in 1 year. Shoot buds derived from calli were used for encapsulation in liquid MS medium containing 3% sucrose and two different alginate matrices (3% sodium alginate (w/v) + MS medium containing 3% sucrose and 3% sodium alginate + 1% activated carbon (w/v) + MS medium containing 3% sucrose) with a 20-min exposure to 2% CaCl2 and 0.3% bavistin (w/v). The capsule with 3.0% sodium alginate (w/v) and 1% activated carbon (w/v) showed a higher conversion rate (61.58%) and stronger plantlets under non-aseptic conditions. These systems are useful for the rapid clonal propagation and dissemination of artificial seed material of P. paniceum for eco-recovery. 相似文献
986.
Shoot tips excised from in vitro cultured plants of Dianthus caryophyllus L. (cv. Pallas, cv. Pink Candy and cv. Wanessa) were successfully cryopreserved using an encapsulation-vitrification method. Shoot tips (2–3 mm in length) were encapsulated in sodium alginate, precultured on liquid Murashige and Skoog (1962) medium supplemented with various sucrose concentrations (0.25, 0.5, 0.75, 1.0 M) for 24 h or 48 h and dehydrated with the vitrification solution PVS2 (up to 4 h) at 24 °C or 0 °C prior to direct immersion in liquid nitrogen (−196 °C). A maximum of shoot regeneration from cryopreserved shoot tips was obtained with the following combinations: preculture in 0.5 M sucrose and 180 min dehydration treatment at 0 °C for cv. Pallas (60% shoot formation), or preculture in 0.75 M and 200 min dehydration at the same temperature for cv. Pink Candy (66.6% shoot formation) and cv. Wanessa (73% shoot formation). 相似文献
987.
Current year shoot cuttings were collected in October and August from three growth habits of peach (Compact, Pillar, and Standard) and treated with one of four concentrations of indole butyric acid (0, 250, 1250, and 2500 mg L−1 IBA). Rooting response was measured after 5 weeks in the greenhouse. Little or no rooting occurred with cuttings from any growth habit that was collected in October or in August when treated with 0 and 2500 mg L−1 IBA. In August, the number of shoots that rooted was greater in cuttings from Pillar (79 and 45%) than Compact (13 and 3%) treated with 250 and 1250 mg L−1 IBA, respectively. Cuttings from Standard trees had intermediate rooting of 56 and 6% at 250 and 1250 mg L−1 IBA, respectively. Pillar trees consistently grew more roots with greater root length per cutting than the other growth habits. It is proposed that differences in rooting response among the growth habits may be associated with differences in endogenous auxin concentration that had been found in previous studies. Within peach and possibly other fruit trees, the capacity of shoot cuttings to develop adventitious roots can vary by cultivar and successful root induction with exogenous plant growth regulators may depend, in part, on endogenous hormone levels. 相似文献
988.
AIM: To investigate the effect of uric acid on the maturation and the biological function of murine bone-marrow derived dendritic cells (BMDCs) in vitro.METHODS: BMDCs were cultured with GM-CSF, IL-4, LPS and uric acid. Cell phenotypes were analyzed by flow cytometry. MTT was used to detect the effect of uric acid on the function of BMDCs in stimulating the proliferation of T cells. IL-12 released by BMDCs was also detected. RESULTS: BMDCs were cultured and identified. Uric acid at concentrations of 200 mg/L and 400 mg/L increased the expression of the molecules (CD11c, CD83, CD86, IA/IE) on BMDCs surface and the IL-12 level in the culture supernatants (P<0.05), promoted the proliferation of T cells at the T: DC rate 5∶1, 10∶1, 20∶1 (P<0.05). However, uric acid at concentration of 70 mg/L had no effect on above molecule expression (P>0.05), no effect on T cell proliferation with BMDCs (P>0.05) was observed. CONCLUSION: Uric acid promotes the differentiation, maturation, the expression of co-stimulatory molecules, the IL-12 production in BMDCs and enhances the ability of BMDCs to stimulate the proliferation of T cell in a specical dose range. 相似文献
989.
AIM: To investigate the preventive effects of Shengmai San (SMS) on oxidative damage in mentally stressed mice.METHODS: An oxidative stress mouse model was established by moustache-removed. Protein carbonyl and thiobarbituric acid reactive substance (TBARS) formation were determined as the oxidative stress markers.RESULTS: (1)Moustache-cut was founded to significantly enhance the behavioral movements of mice, especially large movements (movement 2 and rearing). SMS pre-administration inhibited the accelerated movements. (2) Protein carbonyl was increased in brain, heart, liver and kidney. TBARS in liver and heart increased in the moustache-cut mice, but SMS pretreatment inhibited the increased protein carbonyl and TBARS.CONCLUSION: SMS has the preventive effects on oxidative damage induced by emotional stress. 相似文献
990.
Gabriela Claudia Cangahuala-Inocente Lírio Luiz Dal Vesco Douglas Steinmacher Antonio Carlos Torres Miguel Pedro Guerra 《Scientia Horticulturae》2007
Pineapple guava (Acca sellowiana) syn. Feijoa sellowiana, a Brazilian indigenous Myrtaceae is under domestication in South Brazil. Previous works showed that this species is responsive to somatic embryogenesis and recalcitrant to conventional methods of clonal propagation. In the present work it was evaluated the role of components of culture medium in the induction and development of somatic embryos. The technology of synthetic seeds was also evaluated. Zygotic embryos were inoculated in LPm medium supplemented with 8 mM glutamic acid and 8 mM l-glutamine, 2,4-dichlophenoxiacetic acid (20 μM) and myo-inositol. For conversion of somatic embryos and synthetic seeds it was tested the effect of 6-benzylaminopurine and gibberellic acid combined or not with activated charcoal. The highest values for embryogenetic induction (100%) and number of somatic embryos/explant (113) were observed in the LPm medium supplemented with Glu (8 mM), and 2,4-D. The culture medium supplemented with BA (0.5 μM) and GA3 (1 μM) and activated charcoal (1.5 g L−1) enhanced the conversion of somatic embryos to plantlets. Pre-germinated somatic embryos encapsulated in sodium alginate with BA (0.5 μM) and GA3 (1 μM) developed radicles. The use of synthetic seed was a requisite for the survival of plantlets. 相似文献